Field
The present disclosure relates to valves that are actuated by detonating a pyrotechnic charge. Such valves may be used, for example, in safety systems of nuclear power plants.
Description of Related Art
Conventionally, a shear-type pyrotechnic-actuated valve has an insert portion that is integrally formed with a shear portion. In particular, the insert portion and the shear portion are formed as a monolithic structure and, thus, made of the same material. The insert portion may be demarcated from the shear portion by a groove or other feature designed to provide structural vulnerability for the purpose of facilitating a proper shearing action during actuation. The valve is designed to remain in a closed state until actuated. During actuation, a pyrotechnic charge is detonated to shear off the shear portion to open the valve. The magnitude of the detonation required to open the valve will depend on various factors, such as the bore size of the valve. In this regard, large-bore valves require more pyrotechnic charge in general for actuation compared to small-bore valves of the same material. However, a stronger detonation also results in an increased occurrence of deformation to the insert portion and/or material fragments when the shear portion is sheared off to open the valve during actuation. Consequently, the resulting flow through the opened valve may be hindered, distorted, or otherwise disrupted by the deformation, thereby adversely affecting the intended operation of the valve. Furthermore, the presence of material fragments in the flow may damage or otherwise have a detrimental impact on downstream components and structures.